JP6477176B2 - Power storage device - Google Patents

Description

  The present invention includes an external connection terminal disposed outside a wall portion, a lead terminal protruding outward from the wall portion, a terminal connection member connecting the lead terminal and the external connection terminal, a lead terminal, and an external connection The present invention relates to a power storage device including an outer insulating member wall portion that insulates a terminal and a wall portion.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with battery modules that store electric power supplied to electric motors serving as prime movers. The battery module is configured by electrically connecting secondary batteries as power storage devices with a bus bar. For example, the battery device (secondary battery) of Patent Document 1 includes a metal terminal (terminal connection member) 81 extending from the battery module and a bolt (external connection terminal) penetrating the metal terminal 81, as shown in FIG. 82 and an insulator (insulating member) 84 that insulates between the metal terminal 81 and the casing 83 of the battery module. The insulator 84 includes an engagement protrusion 84 b protruding toward the housing 83, and the engagement protrusion 84 b is inserted into a recess 83 a that is recessed from the surface of the housing 83.

  The metal terminal 81 has a crank shape. The metal terminal 81 includes a fixed piece 81 a, and the fixed piece 81 a is fixed to the housing 83 by a rivet (drawer terminal) 86 through an insulator 84. The rivet 86 includes a pedestal 86a that penetrates the casing 83 and the insulator 84 and is positioned in the casing 83. A terminal (not shown) is connected to the pedestal 86a, and the terminal is electrically connected to the battery cell. It is connected. A gasket 90 is disposed between the pedestal 86 a and the housing 83, and the gasket 90 is in close contact with the outer peripheral surface of the shaft portion 86 b of the rivet 86. The gasket 90 seals the through-hole of the rivet 86 in the housing 83.

  The metal terminal 81 includes a terminal piece 81b and a connection piece 81c that are located farther from the housing 83 than the fixed piece 81a. The bolt 82 includes a hexagonal enlarged portion 82a, a flange portion 82b protruding outward from the enlarged portion 82a along the radial direction of the bolt 82, and a shaft portion 82c having a male screw. The insulator 84 includes a drop prevention portion 85 that comes into contact with the flange portion 82 b of the bolt 82 from below and prevents the bolt 82 from dropping from the metal terminal 81. The drop-off prevention portion 85 has a shape surrounding the enlarged portion 82a of the bolt 82.

  In the battery module of Patent Document 1, the battery cell and the bolt 82 are electrically connected through a terminal (not shown), a rivet 86, and a metal terminal 81, and electricity is transferred. Then, the bolt 82 is inserted into the through hole 88a provided in the bus bar 88, and the bus bar 88 is placed on the terminal piece 81b. By screwing the nut 89 into the shaft portion 82c of the bolt 82, the bus bar 88 is sandwiched between the terminal piece 81b of the bolt 82 and the nut 89, and the bus bar 88 and the metal terminal 81 are electrically connected. . As a result, the battery modules are electrically connected via the bus bar 88.

  Further, in Patent Document 1, in order to suppress the joint rotation of the bolt 82 when the nut 89 is screwed onto the shaft portion 82 c of the bolt 82, the insulator 84 is provided with the drop-off preventing portion 85. Surrounds the enlarged portion 82a and is in contact with the outer surface of the enlarged portion 82a. And in patent document 1, the expansion part 82a of the volt | bolt 82 latches to the inner surface of the drop-off prevention part 85 at the time of nut 89 screwing. At this time, since the rotation of the insulator 84 is restricted by the engagement between the engagement protrusion 84b of the insulator 84 and the recess 83a of the housing 83, the drop prevention portion 85 integral with the insulator 84 causes the bolt The rotation of 82 is restricted, and the joint rotation of the bolt 82 when the nut 89 is screwed is suppressed.

Japanese Patent No. 4670958

  In Patent Document 1, the torque when the nut 89 is screwed is received by the housing 83 from the bolt 82 via the drop-off prevention portion 85 of the insulator 84 and the engagement protrusion 84b. However, when the engagement between the engagement protrusion 84b and the recess 83a cannot be maintained due to the torque at the time of screwing the nut 89, the insulator 84 rotates together. Then, due to the co-rotation of the insulator 84, a stress is generated in the energized portion between the rivet 86 and the metal terminal 81, and there is a possibility that an energization failure occurs in the energized portion. Further, due to the co-rotation of the insulator 84, stress is also generated in the gasket 90 that is in close contact with the shaft portion 86b of the rivet 86, and the gasket 90 is damaged or the position of the gasket 90 is shifted. The sealing performance will be reduced.

  The present invention has been made by paying attention to such problems existing in the prior art, and its purpose is to apply stress to the current-carrying part and the seal part between the terminal connecting member and the extraction terminal when the nut is screwed. An object of the present invention is to provide a power storage device that can suppress the occurrence of water.

  A power storage device for solving the above problems includes an electrode assembly in which electrodes of different polarities are insulated from each other, a case housing the electrode assembly, and an outside of a wall portion of the case. An external connection terminal disposed on the outside of the wall portion so that the bus bar can be fixed and having a male screw portion that can be inserted through the shaft insertion hole of the bus bar, and electrically connected to the electrode assembly in the case And a lead terminal in a state protruding outward from the wall, a terminal connecting member disposed outside the wall and connecting the lead terminal and the external connection terminal, and outside the wall An outer insulating member that insulates the external connection terminal and the wall portion and penetrates the extraction terminal along a protruding direction of the extraction terminal from the wall portion, and the extraction terminal and the inner side of the wall portion Inside to insulate the wall An edge member; and a seal portion that seals a through portion of the lead terminal in the wall portion from the inside of the case, and the wall portion of the case protrudes toward the outside of the wall portion. A first convex portion, and a cylindrical second convex portion protruding from the first convex portion along a protruding direction of the first convex portion from the wall portion. The shape viewed from the protruding direction is a polygonal shape or a shape including a pair of sides extending in parallel, and the planar shape of the second convex portion is more than the planar shape of the first convex portion when the wall portion is viewed from the outer surface. The second convex portion is provided with an insertion hole through which the lead terminal is inserted, and an inner surface surrounding the insertion hole is provided with a clamping surface, and the inner insulating member includes the first convex portion and the second convex portion. Between the inner surface of the lead-out terminal and the outer surface of the lead terminal, and the outer insulating member has the first convex portion inserted therein. And an anti-rotation portion having a shape along the outer surface of the first convex portion, and an engaging concave portion having a shape along the outer surface of the engaging portion into which the engaging portion of the external connection terminal is inserted. The extraction terminal includes a sealing surface facing the clamping surface of the second convex portion along the axial direction of the extraction terminal, and the sealing portion includes the clamping surface of the second convex portion and the extraction terminal. The gist is that it is interposed between the sealing surface.

  According to this, when the nut is screwed to the male screw portion of the external connection terminal, the torque at the time of screwing the nut is received by the rotation preventing portion of the outer insulating member via the locking portion. The outer insulating member is prevented from rotating by the first convex portion of the wall portion being engaged with the inner surface of the engaging concave portion of the outer insulating member. Therefore, the co-rotation of the outer insulating member when the nut is screwed is suppressed. As a result, it is possible to suppress the torque at the time of nut screwing from reaching the extraction terminal penetrating the outer insulating member, and it is possible to suppress the occurrence of stress in the energization portion between the extraction terminal and the terminal connection member. Similarly, the torque at the time of nut screwing is suppressed from reaching the extraction terminal that penetrates the outer insulating member, so that the seal portion that seals the penetration portion of the extraction terminal in the wall portion is It is possible to suppress the torque from being applied and to prevent the sealing performance by the seal portion from being lowered. And the seal part is clamped by the clamping surface of the 2nd convex part, and the sealing surface of an extraction terminal. Since the second convex portion has a smaller planar shape than the first convex portion, the surface pressure acting on the seal portion can be reduced by reducing the area of the sandwiching surface compared to the case where the first convex portion is provided with the sandwiching surface. It can raise and can suppress that the sealing performance of a penetration part falls.

In the power storage device, the inner insulating member may include the seal portion.
According to this, by inserting an inner side insulation member inside the 1st convex part and the 2nd convex part, the insulation function of a wall part and an extraction terminal and the sealing function of the penetration part of an extraction terminal are exhibited. Can do.

  The power storage device is a secondary battery.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a stress generate | occur | produces in the electricity supply part and seal part of a terminal connection member and an extraction terminal at the time of nut screwing.

The disassembled perspective view which shows the secondary battery of embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the component of an electrode assembly. The perspective view which shows an outer side insulation member. (A) is the fragmentary sectional view which shows the inside of the secondary battery of embodiment, (b) is an expanded sectional view which shows the drawer terminal periphery. The figure which shows background art.

Hereinafter, an embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.
As shown in FIG. 1 or FIG. 2, the secondary battery 10 as a power storage device includes a case 11, and an electrode assembly 12 is accommodated in the case 11. The case 11 includes a rectangular box-shaped case main body 14 and a rectangular flat plate-shaped lid member 15 that closes the opening 14 a of the case main body 14. The lid member 15 is joined to the open end of the case body 14 by welding. In addition, the secondary battery 10 of this embodiment is a lithium ion battery. The secondary battery 10 includes a positive terminal structure 16 and a negative terminal structure 17 that exchange electricity with the electrode assembly 12.

  As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 21 and a sheet-like negative electrode 31 which are electrodes having different polarities. The positive electrode 21 has a positive metal foil (aluminum foil in this embodiment) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 31 includes a negative electrode metal foil (copper foil in the present embodiment) 32 and a negative electrode active material layer 33 configured by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 has a laminated structure in which a separator 24 is interposed between the positive electrode 21 and the negative electrode 31 to form a layer.

  The positive electrode 21 has a positive electrode uncoated portion 22 b that is not coated with a positive electrode active material along one side 22 a of the positive metal foil 22. The positive electrode 21 has a tab 25 having a shape protruding from a part of one side 22a. The negative electrode 31 has a negative electrode uncoated portion 32 b that is not coated with a negative electrode active material along one side 32 a of the negative electrode metal foil 32. The negative electrode 31 has a tab 35 having a shape protruding from a part of one side 32a.

  As shown in FIG. 1, the positive electrode tab 25 and the negative electrode tab 35 are provided at positions where the positive electrode tab 25 and the negative electrode tab 35 do not overlap with each other in a state where the positive electrode 21 and the negative electrode 31 are laminated. ing. The positive electrodes 21 constituting the electrode assembly 12 are stacked such that the tabs 25 are arranged in a row along the stacking direction L. Similarly, the negative electrodes 31 constituting the electrode assembly 12 are stacked such that the tabs 35 are arranged in a row along the stacking direction L.

  The secondary battery 10 includes a positive electrode tab group 36. The positive electrode tab group 36 is configured by collecting and stacking all the positive electrode tabs 25 on one end side in the stacking direction L of the electrode assembly 12. Further, the secondary battery 10 includes a negative electrode tab group 36. The negative electrode tab group 36 is configured by collecting and stacking all the negative electrode tabs 35 on one end side in the stacking direction L of the electrode assembly 12.

  A positive electrode conductive member 51 for electrically connecting the electrode assembly 12 and a positive electrode terminal structure 16 described later is joined to the positive electrode tab group 36. The negative electrode tab group 36 is joined with a negative electrode conductive member 51 for electrically connecting the electrode assembly 12 and a negative electrode terminal structure 17 to be described later. Each conductive member 51 has a rectangular plate shape. The conductive member 51 has an insertion hole 52a at one end along the extending direction of the long side, and a later-described lead terminal 61 can be inserted into the insertion hole 52a.

Next, the insulating cover 55 provided in the secondary battery 10 will be described.
As shown in FIG. 1, the secondary battery 10 includes an insulating cover 55 in the case 11, and the insulating cover 55 is interposed between the negative electrode conductive member 51 and the positive electrode conductive member 51 and the lid member 15. ing. The insulating cover 55 has insertion holes 56 at both ends in the extending direction of the long side.

  Next, the positive terminal structure 16 and the negative terminal structure 17 will be described. FIG. 5 illustrates the negative electrode terminal structure 17, but the positive electrode terminal structure 16 is the same as the negative electrode terminal structure 17, and thus illustration thereof is omitted.

  First, the configuration of the lid member 15 for providing the positive terminal structure 16 and the negative terminal structure 17 will be described. As shown in FIG. 1 or FIG. 5A, the lid member 15 has an outer surface 15c facing the outer side of the case 11 and an inner surface 15d facing the inner side of the case 11. The lid member 15 has an outer surface 15c and an inner surface 15d. The direction connecting at the shortest distance is the thickness direction.

  The lid member 15 includes first convex portions 18 on both end sides along the direction in which the long side extends. Each 1st convex part 18 is the cylinder shape which protruded along the thickness direction from the outer surface 15c. When the lid member 15 is viewed from the protruding direction of the first convex portion 18, the planar shape of the first convex portion 18 is a quadrangular shape (polygonal shape). In the 1st convex part 18, the front end surface 18a of the protrusion direction of the 1st convex part 18 from the outer surface 15c is a square ring.

  The lid member 15 includes a second convex portion 19 that protrudes from the tip surface 18 a of the first convex portion 18. When the lid member 15 is viewed from the outer surface 15c, the planar shape of the second convex portion 19 is a quadrangular shape, and the second convex portion 19 is a rectangular tube shape. The first convex portion 18 and the second convex portion 19 have a two-step shape along the protruding direction from the outer surface 15c, and the planar shape of the second convex portion 19 is the first convex when viewed from the outer surface 15c of the lid member 15. It is slightly smaller than the planar shape of the portion 18. The 1st convex part 18 and the 2nd convex part 19 are formed by the drawing process of press work. The second convex portion 19 includes an insertion hole 19 a at the tip in the protruding direction from the lid member 15. Moreover, the 2nd convex part 19 is equipped with the clamping surface 19b in the position which surrounds the insertion hole 19a among the inner surfaces.

  The positive terminal structure 16 and the negative terminal structure 17 include an outer insulating member 57 disposed on the outer surface 15 c of the lid member 15. The outer insulating member 57 is made of synthetic resin. The outer insulating member 57 has a rectangular shape when viewed from the outer surface 15 c of the lid member 15. In the outer insulating member 57, the direction connecting the front surface 57c and the back surface 57a is the thickness direction.

  As shown in FIG. 4, the outer insulating member 57 includes a detent portion 58 near the back surface 57a in the thickness direction. The anti-rotation part 58 has a shape recessed in a square hole shape from the back surface 57a toward the front surface 57c. The quadrangular shape formed by connecting the four inner surfaces of the anti-rotation portion 58 is similar to the quadrangular shape formed by connecting the four outer surfaces of the first convex portion 18. Therefore, the rotation stopper 58 has a shape along the outer surface of the first protrusion 18.

  And as shown in FIG.5 (b), the 1st convex part 18 is inserted inside the rotation prevention part 58 in the outer side insulation member 57. As shown in FIG. The four outer side surfaces of the first convex portion 18 are in contact with and locked with the four inner side surfaces of the rotation preventing portion 58. By this contact, the outer insulating member 57 is restricted from moving in the direction along the outer surface 15c of the lid member 15, in particular, the rotation on the outer surface 15c.

  The outer insulating member 57 includes a through hole 59 closer to the surface 57c in the thickness direction than the rotation stopper 58. When the outer insulating member 57 is viewed from the surface 57c, the through hole 59 has a quadrangular shape. The through hole 59 is continuous with the rotation preventing portion 58 along the thickness direction of the outer insulating member 57. The second protrusion 19 of the lid member 15 is inserted through the through hole 59. The four inner surfaces of the through hole 59 are in contact with and locked with the four outer surfaces of the second convex portion 19. Also by this contact, the outer insulating member 57 is restricted from moving in the direction along the outer surface 15c of the lid member 15, particularly the rotation on the outer surface 15c.

  Moreover, as shown in FIG. 1, the outer side insulation member 57 is provided with the latching rib 57e of the shape standingly arranged from the four side edge part of the surface 57c. The locking rib 57e has a rectangular frame shape when viewed from the outer surface 15c of the lid member 15. The outer insulating member 57 includes a locking recess 57h on the other end side along the direction in which the long side extends. The locking recess 57h has a shape that is recessed from the surface 57c along the thickness direction. The locking recess 57h has a hexagonal shape as viewed from the surface 57c. An external connection terminal 66 described later is locked to the locking recess 57h.

  The positive electrode terminal structure 16 and the negative electrode terminal structure 17 have a rectangular flat terminal connection member 53. The terminal connection member 53 has a back surface 53a facing the outer insulating member 57 and a front surface 53b parallel to the back surface 53a, and a direction in which a straight line connecting the back surface 53a and the front surface 53b with the shortest distance extends is the thickness direction of the terminal connection member 53. And The terminal connection member 53 has an insertion hole 53c at one end in the extending direction of the long side, and a through hole 54 at the other end in the extending direction of the long side. The insertion hole 53c and the through hole 54 penetrate the terminal connection member 53 in the thickness direction.

  The terminal connection member 53 is supported on the surface 57c of the outer insulating member 57 and is accommodated inside the locking rib 57e. The locking rib 57e is in contact with the side edges along the four sides of the terminal connection member 53, and by this contact, the terminal connection member 53 is restricted from moving in the direction along the surface 57c of the outer insulating member 57. The rotation of the member 57 is prevented. In a state where the terminal connection member 53 is prevented from rotating, the insertion hole 53 c of the terminal connection member 53 matches the through hole 59 of the outer insulating member 57.

  The positive electrode terminal structure 16 and the negative electrode terminal structure 17 include an inner insulating member 40 that insulates the inner surfaces of the first and second convex portions 18 and 19 of the lid member 15 from an extraction terminal 61 described later. The inner insulating member 40 is made of rubber and has a rectangular tube shape. In the inner insulating member 40, when the direction in which the central axis extends is an axial direction, the inner insulating member 40 includes a first insulating portion 41 having a rectangular tube shape on one end side in the axial direction and a rectangular tube shape on the other end side in the axial direction. The second insulating part 42 is provided. The first insulating portion 41 and the second insulating portion 42 have a two-step shape along the axial direction of the inner insulating member 40, and the planar shape of the second insulating portion 42 is the first shape when the inner insulating member 40 is viewed from the axial direction. One size smaller than the planar shape of the insulating portion 41.

  When the inner insulating member 40 is viewed from the axial direction, the outer shape of the first insulating portion 41 is a square shape, similar to the rectangular shape on the inner surface of the first convex portion 18 and slightly smaller. Then, as shown in FIG. 5B, the first insulating portion 41 is inserted inside the first convex portion 18 and arranged along the inner surface of the first convex portion 18. When the inner insulating member 40 is viewed from the axial direction, the outer shape of the second insulating portion 42 is a square shape, similar to the rectangular shape on the inner surface of the second convex portion 19 and slightly smaller. The second insulating portion 42 is inserted inside the second convex portion 19 and is disposed along the inner surface of the second convex portion 19.

  The inner insulating member 40 includes an insertion hole 40a at the tip of the second insulating portion 42 in the axial direction. The inner insulating member 40 includes a seal portion 43 at the tip of the second insulating portion 42 in the axial direction, and the seal portion 43 is a portion surrounding the insertion hole 40a. The seal portion 43 is sandwiched in the axial direction of the inner insulating member 40 by the inner surface surrounding the insertion hole 19a and a later-described lead terminal 61 in the second convex portion 19 of the lid member 15.

  The positive terminal structure 16 and the negative terminal structure 17 include a lead terminal 61 that is electrically connected to each tab group 36 of the electrode assembly 12 via a conductive member 51. Assuming that the direction in which the central axis of the lead terminal 61 extends is the axial direction, the lead terminal 61 is electrically connected to the terminal connecting member 53 and the second shaft electrically connected to the conductive member 51. The axial part 63 and the terminal head 64 which connects the 1st axial part 62 and the 2nd axial part 63 are continuously provided in the axial direction.

  The terminal head 64 has a quadrangular prism shape. The terminal head portion 64 includes a flange 64a near the second shaft portion 63 in the axial direction. The outer shape of the flange 64a is a square shape in plan view when the lead terminal 61 is viewed from the direction in which the central axis extends, and the outer shape of the flange 64a is the first convex portion 18 of the lid member 15 and the inner insulating member 40. It is similar to the inner shape of the first insulating portion 41 in plan view and is slightly smaller.

  The terminal head 64 includes a seal surface 64b that surrounds the first shaft portion 62 at the tip in the axial direction, and the seal surface 64b is a quadrangular ring. Further, the outer shape of the terminal head portion 64 other than the flange 64 a is a quadrangular shape in plan view when the lead terminal 61 is viewed from the axial direction, and the outer shape of the terminal head portion 64 is the second shape of the lid member 15. It is similar to the inner shape of the convex portion 19 and the second insulating portion 42 of the inner insulating member 40 in plan view, and is slightly smaller.

  The terminal head 64 of the lead terminal 61 is located inside the second convex portion 19 of the lid member 15 and in the second insulating portion 42 of the inner insulating member 40. Therefore, the terminal head 64 is insulated from the second convex portion 19 of the lid member 15 by the second insulating portion 42 of the inner insulating member 40. That is, the second insulating portion 42 insulates the second convex portion 19 of the lid member 15 from the terminal head portion 64 of the lead terminal 61.

  In addition, the flange 64 a of the lead terminal 61 is positioned inside the first insulating portion 41 of the inner insulating member 40 inside the first convex portion 18 of the lid member 15. Therefore, the flange 64 a is insulated from the first convex portion 18 of the lid member 15 by the first insulating portion 41 of the inner insulating member 40. That is, the first insulating portion 41 insulates the first convex portion 18 of the lid member 15 and the flange 64 a of the lead terminal 61.

  Further, the outer surface of the seal portion 43 of the inner insulating member 40 is sandwiched between the clamping surface 19b of the second convex portion 19 in the lid member 15 and the sealing surface 64b of the lead terminal 61 facing the clamping surface 19b. Yes. Therefore, the seal portion 43 is in close contact with the clamping surface 19b of the second convex portion 19 and the sealing surface 64b of the extraction terminal 61, and by this adhesion, the clamping surface 19b of the second convex portion 19 is sealed, and the extraction terminal The sealing surface 64b of 61 is sealed. For this reason, the insertion hole 19 a of the second convex portion 19 that becomes the penetrating portion of the lead terminal 61 in the lid member 15 is sealed by the seal portion 43 of the inner insulating member 40. In the present embodiment, the seal portion 43 of the inner insulating member 40 is interposed between the clamping surface 19 b of the second convex portion 19 and the seal surface 64 b that is the outer surface of the lead terminal 61.

  Further, the four outer surfaces surrounding the second insulating portion 42 are in contact with the inner surface of the first convex portion 18 facing the outer surface of the second insulating portion 42, and by this contact, the lid member of the inner insulating member 40. The rotation with respect to 15 is restricted. Furthermore, the four side surfaces surrounding the flange 64a are in contact with the four inner side surfaces of the first insulating portion 41 facing the side surfaces. Therefore, the rotation of the lead terminal 61 is restricted by the contact with the inner insulating member 40 whose rotation is restricted with respect to the lid member 15.

  Further, the first shaft portion 62 of the lead terminal 61 passes through the insertion hole 40 a of the inner insulating member 40, the second convex portion 19 of the lid member 15, and the through hole 59 of the outer insulating member 57, so that the terminal connecting member 53 It is inserted through the insertion hole 53c. The first shaft portion 62 includes a first connection portion 62a formed by caulking, and the first connection portion 62a is engaged with the surface 53b of the terminal connection member 53, and the engagement with the lead terminal 61 is achieved by this engagement. The terminal connection member 53 is electrically connected.

  The second shaft portion 63 of the lead terminal 61 passes through the insertion hole 56 of the insulating cover 55 and the insertion hole 52 a of the conductive member 51. The second shaft portion 63 includes a second connection portion 63a formed by caulking, and the second connection portion 63a is engaged with the joined surface of each tab group 36 in the conductive member 51. By this locking, the lead terminal 61 and the conductive member 51 are electrically connected. Therefore, the lead terminal 61 electrically connects the conductive member 51 and the terminal connection member 53, and also connects the terminal connection member 53, the outer insulating member 57, the lid member 15, the inner insulating member 40, and the insulating cover 55. And the conductive member 51 are integrated.

  In the present embodiment, the energization portion M is formed at the contact portion between the terminal connection member 53 and the first connection portion 62a, and the energization portion M is formed at the contact portion between the conductive member 51 and the second connection portion 63a. Has been.

  The positive terminal structure 16 and the negative terminal structure 17 include an external connection terminal 66 connected to the terminal connection member 53. The positive external connection terminal 66 is electrically connected to the positive electrode tab group 36 of the positive electrode 21 through the terminal connection member 53, the lead terminal 61, and the conductive member 51. The negative external connection terminal 66 is electrically connected to the tab group 36 of the negative electrode 31 via the terminal connection member 53, the lead terminal 61, and the conductive member 51.

  The external connection terminal 66 is disposed on the outer surface of the lid member 15 so that the bus bar 60 can be fixed outside the lid member 15. The bus bar 60 has a rectangular plate shape. The bus bar 60 includes shaft portion insertion holes 60a at both ends in the direction in which the long side extends.

  The external connection terminal 66 is made of metal. The external connection terminal 66 includes a hexagonal columnar locking portion 67 and a male screw portion 68 serving as a shaft portion protruding from the locking portion 67 in a state of being continuous in the axial direction of the external connection terminal 66. A nut 70 for fastening the bus bar can be screwed into the male screw portion 68. The male screw portion 68 protrudes outward from the surface 57 c of the outer insulating member 57.

  The locking portion 67 is accommodated in the locking recess 57 h of the outer insulating member 57. The shape of the locking portion 67 when the external connection terminal 66 is viewed from the axial direction is similar to the hexagonal shape of the locking recess 57h, and the locking portion 67 is accommodated in the locking recess 57h. Therefore, the locking recess 57 h has a shape along the outer surface of the locking portion 67. Then, the six side surfaces of the locking portion 67 are in contact with the six inner side surfaces of the locking recess 57h, and this contact restricts the movement of the external connection terminal 66 in the direction along the outer surface 15c of the lid member 15, The rotation around the axis of the external connection terminal 66 is restricted. The dimension (thickness) of the locking portion 67 along the axial direction of the external connection terminal 66 is the same as the depth from the surface 57c of the locking recess 57h. For this reason, in the latching | locking part 67, the exposed surface from the surface 57c of the outer side insulation member 57 is flush with the surface 57c.

Next, the operation of the secondary battery 10 will be described.
Different secondary batteries 10 are electrically connected by a bus bar 60. Then, in the secondary batteries 10, the male screw portion 68 of the positive external connection terminal 66 is inserted into one shaft portion insertion hole 60 a of the bus bar 60, and another secondary battery 10 is inserted into the other shaft portion insertion hole 60 a. The male screw portion 68 in the negative external connection terminal 66 is inserted. The bus bar 60 is supported on the surface 53 b of the terminal connection member 53.

  As shown in FIG. 5A or FIG. 5B, the nut 70 is screwed to each male screw portion 68, whereby the bus bar 60 is sandwiched between the nut 70 and the terminal connection member 53. The bus bar 60 is electrically connected to the terminal connection member 53. Torque for screwing the nut 70 is received by the outer insulating member 57 locked to the locking portion 67 of the external connection terminal 66. Here, the outer insulating member 57 is locked to the first convex portion 18 of the lid member 15 and is prevented from rotating. As a result, the joint rotation of the external connection terminal 66 and the outer insulating member 57 is suppressed.

According to the above embodiment, the following effects can be obtained.
(1) The secondary battery 10 includes a first protrusion 18 and a second protrusion 19 that protrude in two steps from the lid member 15. The first convex portion 18 has a rectangular cylindrical shape, and the outer insulating member 57 is prevented from rotating by the engaging concave portion 57 h of the outer insulating member 57 engaging with the outer surface of the first convex portion 18. For this reason, the torque at the time of screwing the nut 70 is received by the first convex portion 18 of the lid member 15 via the outer insulating member 57, and not only the external connection terminal 66 but also the outer insulating member 57 rotates. Can be suppressed. Therefore, it is possible to suppress the torque at the time of screwing the nut 70 against the lead terminal 61 that has penetrated the outer insulating member 57. Therefore, it is possible to suppress the occurrence of stress in the energization portion M between the extraction terminal 61 and the terminal connection member 53 due to the torque when the nut 70 is screwed, and the occurrence of energization failure is suppressed.

  Moreover, since it is suppressed that a torque reaches the extraction terminal 61, it can suppress that a stress generate | occur | produces in the seal part 43 closely_contact | adhered to the sealing surface 64b of the extraction terminal 61. FIG. And the clamping surface 19b of the 2nd convex part 19 which clamped the seal | sticker part 43 has an area smaller than the front end surface 18a of the 1st convex part 18. FIG. For this reason, when the seal portion 43 is held between the holding surface 19b of the second convex portion 19 and the seal surface 64b of the lead terminal 61, the surface pressure acting on the seal portion 43 can be increased, and the seal of the seal portion 43 Performance can be increased.

  (2) The energizing portion M between the lead terminal 61 and the terminal connecting member 53 and the energizing portion M between the lead terminal 61 and the conductive member 51 have the first convex portion 18 that prevents the outer insulating member 57 from rotating in the axial direction. It exists in the position to pinch. For this reason, even if the torque at the time of screwing the nut 70 is received by the first convex portion 18, the torque does not easily reach the energizing portion M.

  (3) The 1st convex part 18 and the 2nd convex part 19 are the 2 steps | paragraphs shape which protruded from the outer surface 15c of the cover member 15, and are formed by a drawing process. The first convex portion 18 prevents the outer insulating member 57 from rotating, and the second convex portion 19 increases the surface pressure of the seal portion 43 that seals the penetrating portion of the lead terminal 61 in the lid member 15. Therefore, while the two convex portions are formed at one place of the lid member 15, the functions exerted by the first convex portion 18 and the second convex portion 19 can be made different. Therefore, unlike the case where each function is provided in the lid member 15 separately, the lid member 15 can be easily manufactured.

  (4) The inner insulating member 40 is disposed in the first convex portion 18 of the lid member 15 and covers the outer surface of the flange 64 a of the lead terminal 61 and the second convex portion 19 of the lid member 15. And a second insulating portion 42 that covers the outer surface of the terminal head 64 of the lead-out terminal 61. The inner insulating member 40 insulates the lid member 15 and the lead terminal 61 from each other. Therefore, even if the lid member 15 has a two-stage shape including the first convex portion 18 and the second convex portion 19, and the lead terminal 61 also has a two-stage shape including the flange 64a and the terminal head 64, the inner insulating member. The lid member 15 and the lead terminal 61 can be insulated by one member of 40.

  (5) The inner insulating member 40 insulates the lid member 15 and the lead terminal 61 with the first insulating portion 41 and the second insulating portion 42, and the lid member 15 with the seal portion 43 integral with the second insulating portion 42. The through portion of the lead terminal 61 is sealed. Therefore, the number of parts of the secondary battery 10 can be reduced as compared with the case where the insulation between the lid member 15 and the lead terminal 61 and the sealing of the penetrating portion of the lead terminal 61 at the lid member 15 are performed by separate members. In addition, the secondary battery 10 can be easily manufactured.

  (6) The 2nd convex part 19 which protruded from the 1st convex part 18 is also a square cylinder shape, and the terminal head 64 inserted inside the 2nd convex part 19 is also a square pillar shape. For this reason, the co-rotation of the outer insulating member 57 can also be suppressed by the contact between the side surface of the terminal head 64 and the inner surface of the second convex portion 19. Therefore, compared to the case where the co-rotation of the outer insulating member 57 is suppressed only by the contact between the first convex portion 18 and the anti-rotation portion 58, the co-rotation of the outer insulating member 57 is easily suppressed, and the outer insulating member 57 and The stress generated in the lead terminal 61 can be relaxed.

In addition, you may change the said embodiment as follows.
○ The lead terminal 61 has a plan view shape when viewed from the axial direction, and the flange 64a has a quadrangular shape. These shapes may be triangular, pentagonal, hexagonal, octagonal, and other polygonal shapes. Good. Alternatively, the planar view shape of the flange 64a may be a shape having a pair of sides extending in parallel to each other, and may be a quadrilateral shape, an elliptical shape or an oval shape in addition to the hexagonal shape of the embodiment. It may be. In these cases, the shape of the locking recess 57h of the outer insulating member 57 is changed in accordance with the shape of the flange 64a.

  ○ The lead terminal 61 has a planar shape when viewed from the axial direction, and the terminal head 64 may not be a quadrangular prism, but may be a cylindrical shape, a triangular shape, a pentagonal shape, a hexagonal shape, an octagonal shape, or other polygonal shapes. . Alternatively, the terminal terminal 64 may have a pair of sides extending in parallel with each other in a plan view shape when the extraction terminal 61 is viewed from the axial direction, and may be an elliptical column shape or a long column shape.

  O The external connection terminal 66 has a planar shape when viewed from the axial direction, and the locking portion 67 may have a triangular prism shape, a quadrangular prism shape, a pentagonal prism shape, an octagonal shape, or other polygonal shapes instead of a hexagonal prism shape. Alternatively, the external connection terminal 66 may have a planar shape when viewed from the axial direction, and the locking portion 67 may have a pair of sides extending in parallel with each other, or may have an elliptical column shape or an oblong column shape. .

  In the embodiment, the inner insulating member 40 is integrally provided with the seal portion 43, and insulation of the lid member 15 and the extraction terminal 61 and sealing of the penetration portion of the extraction terminal 61 in the lid member 15 are a member of the inner insulation member 40. I also used it. Not limited to this, the inner insulating member 40 may be used only for insulating the lid member 15 and the lead terminal 61, and another member such as an O-ring or a gasket may be provided for sealing the through portion.

  ○ The outer insulating member 57 is provided with a rectangular frame-shaped locking rib 57e that surrounds the entire terminal connecting member 53. The locking rib 57e prevents the terminal connecting member 53 from rotating, but if the terminal connecting member 53 can be prevented from rotating, The locking rib 57e does not have to be a square frame shape. For example, it may be two locking ribs 57e that can come into contact with a pair of side edges along the long side of the terminal connecting member 53, or L-shaped provided at four locations along the four corners of the outer insulating member 57. It may be a shaped locking rib 57e.

  The connection between the first connection portion 62a of the lead terminal 61 and the terminal connection member 53 and the connection between the second connection portion 63a and the conductive member 51 for forming the energization portion M is not caulking but welding or screwing. It may be.

  In the embodiment, the positive electrode 21 has the positive electrode active material layer 23 on both sides of the positive electrode metal foil 22, but may have the positive electrode active material layer 23 only on one side of the positive electrode metal foil 22. Similarly, the negative electrode 31 has the negative electrode active material layer 33 on both sides of the negative electrode metal foil 32, but may have the negative electrode active material layer 33 only on one side of the negative electrode metal foil 32.

  In the embodiment, the secondary battery 10 is a lithium ion secondary battery, but is not limited thereto, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer 23 and the negative electrode active material layer 33 through the separator 24 and the electrolytic solution, and charge is transferred.

The electrode assembly 12 may be a wound type instead of a laminated type.
The wall portion of the case 11 may be the side wall of the case body 14 instead of the lid member 15.
The power storage device may be applied to other power storage devices such as an electric double layer capacitor.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The outer insulating member includes a locking rib that is locked to a side edge of the terminal connecting member, and the outer insulating member of the outer insulating member is locked by the locking of the side edge of the terminal connecting member and the locking rib. A power storage device in which rotation of the terminal connecting member in a direction along the surface is restricted.

  (B) The storage rib is a power storage device having a frame shape surrounding the terminal connection member.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Case, 12 ... Electrode assembly, 15 ... Cover member as wall part, 18 ... 1st convex part, 19 ... 2nd convex part, 19a ... Insertion hole, 19b ... Clamping surface, 21 ... positive electrode as electrode, 31 ... negative electrode as electrode, 40 ... inner insulating member, 43 ... seal part, 53 ... terminal connecting member, 57 ... outer insulating member, 57h ... locking recess, 58 ... non-rotating part, 60 ... Bus bar, 60a ... Shaft insertion hole, 61 ... Lead terminal, 64b ... Seal surface, 66 ... External connection terminal, 67 ... Locking part, 68 ... Male thread part, 70 ... Nut.

Claims (3)

An electrode assembly in which electrodes of different polarities are laminated with each other insulated from each other;
A case containing the electrode assembly;
An external connection terminal that has an external thread portion that is disposed outside the wall portion so as to be fixable on the outside of the wall portion of the case and that can be inserted into the shaft insertion hole of the bus bar;
A lead terminal electrically connected to the electrode assembly in the case and protruding outward from the wall; and
A terminal connecting member disposed outside the wall and connecting the lead-out terminal and the external connection terminal;
An outer insulating member that insulates the external connection terminal and the wall portion outside the wall portion, and through which the lead terminal penetrates along a protruding direction of the lead terminal from the wall portion;
An inner insulating member that insulates the lead terminal and the wall inside the wall;
A seal portion that seals the through portion of the lead terminal in the wall portion from the inside of the case;
The wall portion of the case has a cylindrical first convex portion protruding toward the outside of the wall portion,
A cylindrical second convex portion projecting from the first convex portion along the direction of projection of the first convex portion from the wall portion,
The first protrusion is a shape including a pair of sides extending in parallel with a polygonal shape as viewed from the protruding direction,
When the wall portion is viewed from the outer surface, the planar shape of the second convex portion is smaller than the planar shape of the first convex portion, and the second convex portion has an insertion hole through which the extraction terminal is inserted, A holding surface is provided on the inner surface surrounding the hole,
The inner insulating member is interposed between inner surfaces of the first and second convex portions and an outer surface of the lead terminal,
The outer insulating member has the first convex portion inserted therein, and a detent portion having a shape along the outer surface of the first convex portion, and a latch portion of the external connection terminal, and the latch portion. A locking recess having a shape along the outer surface of
The extraction terminal includes a sealing surface facing the clamping surface of the second convex portion along the axial direction of the extraction terminal,
The power storage device, wherein the seal portion is interposed between the clamping surface of the second convex portion and the seal surface of the lead terminal.   The power storage device according to claim 1, wherein the inner insulating member includes the seal portion.   The power storage device according to claim 1, wherein the power storage device is a secondary battery.